Clamp or hook for printing plates



`Jllne 9, 1936. i A, J, HOERTH 2,043,660

CLAMP OR` HOOK FOR PRINTING PLATESV June 9, 1936. A. J. HoERTH 2,043,660

CLAMP OR HOOK FOR PRINTING PLATES Filed om. 15, 19:54 s sheets-sheet 2ad 16 Pff w" l@ l IMJ nrmrunnmnl 59 j- 67 fik? 69 5 f Y Hg J5 i9 if 5vall Jy @7 jly @9 7 J3 gv 5g s @a 17 .M 476 i f2 @f fe M 47651 Jg JJ J fL z/efafaz@ June 9, 1936. A, J. HOERTH 2,043,660

CLAMP OR HOOK FOR PRINTING PLATES Filed Oct. l5, 1934 75 Sheets-Sheet 3j' .15 7g fg Patented June 9, 1936 UNITED STATES PATENT OFFICE Albert J.Hoerth, Chicago, Ill., assignor to A. J.

Hoerth and Company, Chicago, Ill., a corporation of Illinois ApplicationOctober 15, 1934, Serial No. 748,300

5 Claims.

'I'his invention relates to clamps or hooks for printing plates andparticularly to such clamps or hooks which are used for securingprinting plates upon base plates which are provided with slots.

In the printing art such base plates may be either flat or cylindricaland may be provided with parallel or helical slots. These slots areundercut. The clamps to which this invention relates can be movablylocated in the slots and are provided with means for abutting againstprinting plates to hold them firmly on the base plate. In the printingtrade these clamps are usually called hooks.

One of the objects of the invention is to provide an improved printingplate clamp.

A further object of the invention is to provide a printing plate clampcapable of internal adjustment whereby the plate-engaging means may beremoved and adjusted independently of the main body of the clamp.

Other objects, advantages and capabilities of the invention will readilyappear from the following description of preferred embodiments thereof,taken in conjunction with the accompanying drawings, in which Figure 1is a front view of a base plate assembly showing the manner in whichprinting plates are mounted thereon by means of the clamps;

Fig. 2 is an enlarged sectional view of a plate clamp embodying theinvention, shown in operative position within the slot of a base plate;

Fig. 3 is a transverse section taken `on the line 3-3 of Fig. 2;

Fig. 4 is a plan view, on a smaller scale, of the clamp shown in Figs. 2and 3;

Fig. 5 is a side elevational View of the clamp illustrated in Figs. 2, 3and 4, on the same scale as that employed in Fig. 4, illustrating themanner in which the clamping member is adjusted;

Fig. 6 is a longitudinal sectional view similar to Fig. 2, showing afurther embodiment of the invention;

Fig. 7 is a transverse sectional View of Fig. 6, taken on the line 'I-'lof Fig. 6;

Fig. 8 is a plan View on a smaller scale, showing the clamp mounted inthe base plate;

Fig. 9 is an elevational view of the clamp illustrated in Figs. 6, '7and 8 and showing the manner in which the clamping member is adjusted.

Fig. 10 is alongitudinal sectional view, similar to Figs. 2 and 6,showing a further embodiment of the invention;

Fig. 11 is a transverse sectional view taken on the line II--II of Fig.10;

Fig. 12 is a plan view on a smaller scale showing the clamp mounted inthe base plate;

Fig. 13 is a sectional view through the base plate, taken on the lineI3-I3 of Fig. 10, showing the clamp in elevation, and

Fig. 14 is an elevational view of the clamp illustrated in Figs. 10 to13, inclusive, on the same scale as that employed in Fig. 12,illustrating the manner in which the clamping member, is adjusted.

Referring to Fig. 1 of the drawings, the reference numeral I indicates abase plate of known type which is provided with slots I I. Theseparticular base plates are flat, but it will be understood thatcylindrical base plates having helical slots of similar cross sectionare well known in the art. The clamps or hooks of the present inventionare adapted for use with both types of base plates.

As shown in Fig. 3, the slot II of one Wellknown type of base plate isprovided near the surface of the plate with overhanging lips I 2. 'Ihebottom of the slot II is undercut for the reception of an insert stripI3 which is provided with upwardly directed rack teeth I 4 adjacent eachside of the slot. The plates I0 are usually made of aluminum and thestrips I3 are usually steel. The clamp illustrated in Figs. 2 to 5inclusive, is intended for use with such a plate. This clamp comprises amain body I and a carriage I6 slidably mounted therein for movement inthe longitudinal direction of the slot.

The main body I5 is provided with a longitudinal recess I1 which opensto the top and one end of the body, and the carriage I6 is mountedwithin this recess. The side walls of the recess I 'I have longitudinalgrooves I8 cut therein for the reception of tongues I9 on the carriageI6. Adjacent the bottom of the recess I1 is located a threaded rod 20,one end of which is rigidly mounted in the main body I5, being securedthereto by means of a pin 2|. The rod 20 is operatively engaged by a nut22 which is rotatably mounted on a depending portion 23 of the carriageI 6.

The nut 22 is provided at one end with a bevel gear 24. Its other endrigidly receives a collar 25 which secures the nut permanently upon thecarriage I 6. The bevel gear 24 meshes with a bevel gear 26 which ispressed upon the reduced end 21 of a hollow pin 28. The pin 28 extendsthrough the body of the carriage I6 and is suitably shouldered so as toprovide a mounting for the pin 28 and bevel gear 26, which provides forthe free rotation thereof. The bevel gear 26 may be permanently mountedon the pin 28 by spreading the lower reduced end of the pin. 'Iheopening in the pin 28 is suitably of square or other non-roundcross-section so that it may be rotated by means of the crank 29 shownin Fig. 5, which crank comprises a rod 3B of similar cross-section. Atits upper end the pin 28 is provided with an annular shoulder 3l whichis received in an annular recess in the surface of a clamping plate 32which clamping plate is freely rotatable on the pin 28. The clampingplate 32 is preferably undercut along one longitudinal edge. as shown at33 in Fig. 3.

The main body I5 is provided with a horizontal slot 34 which receives alatch member 35. The slot 34 and latch member 35 are normally locatedbelow the level of the overhanging lips I2 so that by suitablemanipulation the ends of the latch member 35 may be brought under theselips, as shown in Fig. 4, so as to maintain the clamp withinthe slot II.

The latch member 35 is preferably rigidly mounted on a pin 36 which hasa pressed fit in a central opening in the latch member 35. The

l pin 36 passes through an opening 31 which extends from the uppersurface of the main body I5 into the slot 34. The pin 36 has a centralopening 38 of square or non-round cross-'section whereby the latch 35may be actuated by a suitable tool. It is preferred that the opening inthe hollow pin 28 and the opening 38 should be of the same cross-sectionso that a single crank 29 may be used for actuating the gears 22 and 26and the latch member 35. At the lower end ofthe main body I5, teeth 39are cut, which teeth are adapted to register with the rack teeth I4 ofthe insertl strip I3.

In use, the hook or clamp which has just been described is placed byhand in an appropriate position in one of the slots I I, that is, aposition which brings the beveled edge 33 of the clamping plate 32 veryclose to the desired position of one of the printing plates 49 which areto be mounted on the base plates I3. If it is desired to move the clampor hook bodily, this may easily be done by lifting it manually out ofthe slot II and moving it along the slot. When again set down in theslot, the teeth 39 of the clamp engage the rack teeth I4 of the insertstrip I3. The latch member 35 is rotated into the position shown indotted lines in Fig. 4, and the engagement of the latch member with theoverhanging lips lI2 secures the clamp against upward displacement fromthe slot II.

In order to adjust the clamping plate 32 very accurately, the crank 29is inserted in the opening of the pin 28 and it is rotated in theappropriate direction. This rotation causes corresponding rotations ofthe bevel gears 26 and 24 and the rotation of the nut 22. The rotationof the nut 22, which is in operative engagement with the stationarythreaded bar 29, causes the carriage I6 to slide, one way or the other,upon the main body I5 of the clamp. It will readily be understood thatVery minute adjustments of the clamping plate 32 may be made in thismanner and that thereby the position of the printing platev49 upon thebase plate I8 may be very aocurately controlled. It may here be notedthat a very high degree of accuracy is necessary in this relation,particularly in color work where impressions in several colors are madein succession. This adjustment of the clamping plate 32 enables thesuccessive impressions to be brought into very perfect register. I findthat a single latch member 35 is adequate to maintain the clamp in theslot 3D. This fact is due to the location of the clamping plate 32remote from the latch member 35. The pressure exerted by the printingplate 49 against the clamping plate 32 and the adjacent parts of theclamp, causes one end of the clamp to be forced downwardly towards therack teeth I4. Any tendency of the clamp to turn as a whole iseffectively prevented by the single latch member 35.

The embodiment of the invention illustrated in Figs. 6 to 9 inclusive,is intended for use with a base plate 4I having a somewhat differenttype of slots 42. These slots are not provided with lips adjacent thesurface of the base plate but they are grooved to receive insert strips43 which are provided with rack teeth 44 which become located on thesides of the slots 42 and extend longitudinally thereof. This clampcomprises a main body 45 and a carriage 46 slidably mounted i therein.In plan the main carriage is of substantial U-shape, comprising sidemembers 41 and an end member 48. The side members 41 are connectedrigidly together by means of pins 49 which rigidly mount to and betweenthe side members 41, a longitudinal rack 58 which is adapted tocooperate with a helical gear 5 I which will hereinafter be more fullydescribed.

The carriage 45 rides in the recess 52 provided between the two sidemembers `41 and is provided with tongues 53 which slide in grooves 54located in these side members.

On the outer sides of the side members 41 are cut a Series of teeth 55which correspond to, and

are adapted to engage, the teeth 44 of the insert strip 43 when theclamp is dropped into one of the slots 42. It will be seen thatY owingto the engagement of the teeth 55 and 44 the main body 45 of the clampis held against movement in the slot and before it can be moved bodilyto another position, the clamp mustbe elevated to bring the teleth 55and 44 out of engagement.

The main body 45 is cut away at one end on the level of the lower faceof the teeth 44, as shown at 56 in Fig. 6, to provide a suitableposition for the mounting of a latching member 51. This latching memberis rigidly mounted on the lower reduced end of a pin 58 which extendsthrough a vertical opening 55 in the main body 45. The pin 58 isprovided at its upper end with a flange 80 which is received in anannular recess in the top surface of the main body 45. The pin 58 isprovided with square or other non-round opening 6I for the reception ofa crank 62 whereby the latch member 5l may be rotated into and out oflatching postion. In latching position the ends ofthe latching member 51are projected below the teeth 44 so as to engage these teeth and holdthe clamp against upward movement.

It will be understood that in this modification a clamping plate63,similar to the clamping plate 32 of the previously describedmodification, is employed and that this clamping plate is located inspaced relation with respect to the latching member 51. When the clampis in use to hold a printing plate upon the base plate 4I, the latchingmember 51 prevents upward movement of one end of theV clamp and theprinting plate forces the other end of the clamp downwardly into thebase plate. Y

The carriage 46 comprises a body which is recessed as at 64, for theaccommodation of the helical gear 5I. This helical gear is rotatablymounted upon a shaft .65 which extends across the recess 64 and whichmay suitably have a pressed t in openingsin portions of the carriagevThe Worm Wheel 83 is adapted to be operated by which form the sides ofthe recess64. 'I'his helical gear is located so as operatively to engagethe rack 59.

The helical gear 5| is operated by a Worm 86 which is located in a bore|51 extending from the upper face of the carriage into the recess 64.The lower end of the worm is reduced and `is provided with a bearing inanV opening 88 in the carriage.

The worm 66 is held in position by-rneans ofpins 69 driven into thecarriage 46 and passing through an annular groove on the surface-of theworm. The upward end of the worm is provided with a flange which islocated in the recess in the upper surface of the clamping plate |33. Itwill be understood that the clamping plate 63 ismOunted for freerotation upon the upper part of the worm (it. The upper part of the worm66 is provided Q ,with a square or non-round opening 19, which is 2preferably the same in cross-section as the opening 6|, so that both maybe actuated by the same crank 62.

The operation of this embodiment of the invention is substantiallysimilar to that of the embodiment first described. In short, the clampis inserted in the slot in the base plate at a suitable location andrough adjustment is provided by merely unlocking the latching member 51and lifting the clamp by hand to disengage the teeth 44 and 55. Aft-erlocating the clamp in the desired position, the latching member 51 isturned into the position shown in dotted lines in Fig. 8 so as to lockthe clamp in that position. Fine adjustment of the clamping plate 63 isattained by actuation of the worm 66, which has the effect of operatingthe helical gear 5|. The direct engagement of the `helical gear 5| withthe rack 5i! causes the desired slight movement of the carriage 43 withrespect to the main body 45.

The embodiment of the invention illustrated in Figs. 10 to 14 inclusive,comprises a main body 1| on which is slidably mounted a carriage 12. Themain body is provided with teeth 13 on each side which are adapted toengage with the teeth of rack strips 14 which are inserted inside of thegroove 15 of the base plate 16. The main body is provided with shoulders11 on each side, which shoulders are adapted to rest upon the upper endsof the teeth of strips 14. It will thus be seen that once placed inposition, the main body 1| is not movable in the slot 15, but must belifted out of the slot in order to be moved to a different positiontherein. It must be understood that this embodiment of the invention isnot limited to the main body 1| being provided with teeth on its sides.It will be obvious that this embodiment of the invention may be adaptedfor use with a slotted base plate of the type shown in Figs. 2 to 4inclusive, the main body 1| being provided with teeth on its lower faceso as to engage the upwardly directed teeth in the bottom of slots ofbases of this type.

The main body 1| is provided with a central longitudinal rack 18 and ischambered thereabove, as indicated at 19, for the reception of thesliding carriage 12. The sliding carriage 12 is provided with guideelements 89 which project into grooves 8i formed in the sides of themain body, these grooves opening inwardly into the chamber 18. Thesliding carriage 12 is slotted as shown at 82, to provide for themounting on the carriage of a worm wheel 83. This worm wheel 83 isadapted to cooperate with the rack 18 so as to effect the movement ofthe carriage 12 relative to the main body 1|.

a worm 84 mounted in the main carriage in a suitable manner, forexample, in the same way as the Worm 68 of the embodiment illustrated inFigs. 6 to 9, inclusive. The shaft of the worm 84 is provided with anon-round opening 85 whereby the Worm may be actuated by a suitablecrank S8 in the manner shown in Fig. 14.

A characteristic of this embodiment of the inventionis that the clampingplate 81 is mounted on the carriage 1| at the end thereof which movesoutwardlyaway from the main body 1| during normal operation. Theclamping member 81 is held in position by means of a pin 88, which mayalso suitably rigidly carry a latching element 89. In this particularembodiment, the latching element 89 is adapted to be turned by the pin88 so that it may extend underneath the teeth of the racks 14, in themanner shown in Fig. ll. It will readily be understood that thislatching element may be located at a higher level in order to cooperatewith overhanging'lips in the case of a base plate of the type shown inFigs. 2, 3 and 4. The pin 88 is, of course, provided with a nonroundopening so that it may be actuated by a suitable crank.

It will be noted with particular reference to Fig. l0, that in thisembodiment of the invention the plate 40 does not overlie any part ofthe clamp or hook. This results from the fact that the clamping plate 81is mounted at the outward extremity of the carriage 1 I. The clamp can,therefore, be readily removed and replaced in a more suitable position.All that it is necessary to do is to manipulate the latching member 89and lift the Whole clamp bodily upwards. This may readily be done bygrasping the clamping plate 81 by the fingers. After the main body islocated in a suitable position, the crank 86 is engaged in the opening85 of the worm 84 and rotated so as to bring the clamping plate 81 intofirm engagement with the printing plate 49.

It is normally preferred to provide freedom of adjustment of thecarriage upon the main body in both directions. To facilitate this aim Iprefer to provide marks 90 on the upper surface of the carriage and mainbody. When these marks are brought into register, the carriage ispractically at the center of its range of movement. The operator mayadjust the clamping members to bring these lines into alignment,whereupon he can be sure of ability to move the carriage to a knownextent in both directions.

A further feature of this embodiment is that the carriage is lockeddirectly to the base plate. It may here be noted that the latchingmember 39 is located below the clamping plate 81 and prevents the clampas a whole from being moved upwardly at this end. The effect of theprinting plate 40 against the clamping plate 81 is to force the end ofthe clamp remote from the clamping plate, downwardly into the slot 15.It is not considered necessary, therefore, to provide a latching memberat both ends of the clamp, but this may be done if desired.

Although the invention has been disclosed in connection with thespecific details of preferred embodiments thereof, it must be understoodthat such details are not intended to be limitative of the inventionexcept in so far as set forth in the accompanying claims.

I claim:

1. A clamp or hook for securing printing plates to slotted base platesprovided with teeth therein, comprising a main body adapted to bedropped into a slot, said main body having means adapted to engage saidteeth to render the body immovable along the slot, locking means forsecuring said main body against upward movement, a carriage slidablymounted on said main body, and a clamping plate mounted on said carriageand adapted to engage a printing plate in securing relation.

2. A clamp or hook for securing printing plates to slotted base plateshaving inwardly directed teeth, comprising a main body adapted to bedropped into a slot, teeth on said main body engaging rst said teeth toprevent longitudinal movement of therbody in the slot, latching meansfor securing said main body in a slot against vertical movement, acarriage slidably mounted on the main body, and a clamping member onsaid carriage.

3. A clamp or hook for securing printing plates to slotted base plateshaving inwardly directed teeth, comprising a main body adapted to bedropped into a slot, teeth on said main body engaging first said teethto prevent longitudinal movement of the body in the slot, latching meansfor securing said main body in a slot against vertical movement, acarriage slidably mounted on the main body, a non-reversible drive foreiecting movement of the carriage relative to the main body, and aclamping member on the carriage.

4. A clamp or hook for securing printing plates to slotted base plates,comprising a main body, a carriage slidably mounted on the main body, aclamping member on said carriage, and means mounted on the slidingcarriage for securing the clamp in the slot.

5. A clamp or hook for securing printing plates to slotted base plateshaving teeth in the slots, comprising a main body provided with teethadapted to engage said teeth, latch means securing the clamp to the baseplate, a carriage slidably mounted on the main body, a non-reversibledrive for effecting movement of the carriage relative to the main body,and a clamping member on the carriage.

ALBERT J. HOERTH.

